Have a little problem with my 95 chevy TBI with a 4l60e Trans. Just threw in a 350 crate motor truck has 38s when im out on the trails when i get into the throttle its like a dogg. But if i start off in 1st gear its all there. For some reason it doesnt want to down shift on its own. Any ideas? Maybe it needs a shift kit or is something wrong? i did not hook up the o2s when i put the new motor in because i ran new exhaust. I also installed a new fuel system new pump lines fuel filter and fuel regulator rebuild kit. because the pump took a shit.....